1. Field of the Invention
The present invention relates to a support for supporting a power tool, in particular, a percussion power tool such as, e.g., a hammer drill for forming blast bores in mining industry, on a displacement carriage.
2. Description of the Prior Art
Conventionally, heavy hammer drills, which weigh more than 10 kg such as used in the mining industry, a releasably mounted on displacement carriages having a spindle drive for self-propelled displacement for forming bores. The power tools, which are pneumatically or electrically driven, are high-powered tools and are usually air- or water-cooled.
European Publication EP 107629 discloses a hammer drill with a pneumatic percussion mechanism and having a brushless, air-cooled electric motor electronically commutated via an inverted rectifier.
U.S. Pat. No. 3,880,244 discloses a percussion power tool that is releasably mounted on a displacement carriage displaceable by a hydraulic motor via a threaded rod. However, there is no delivery of cooling medium from the carriage to the power tool.
German Publication DE 36 12 762 discloses a percussion power tool driven by a hydraulic motor and supported on a displacement carriage by support means. The displacement carriage is displaced by a threaded rod driven by another hydraulic motor. No delivery of fluid through the support arm to the power tool takes place.
International publication WO 96/06714 discloses a water-cooled electrical core drill supported on a displacement carriage by a support. The tool support is formed as a fork-shaped mount connected with the carriage by a bolt extending through an eyelet provided on the carriage. The bolt is provided with partially axial and radial lubrication bores which open at the cylindrical outer surface of the bolt for lubricating the support. There is no flow of the drilling or cooling medium or fluid to the power tool itself.
Accordingly, an object of the present invention is to provide a support for supporting a power tool on a displacement carriage and including means for delivering a drilling or cooling fluid to the power tool.
This and other objects of the present invention, which will become apparent hereinafter, are achieved by providing a support for supporting a power tool on a displacement carriage and including attachment means for connecting the power tool with the carriage, and a bolt insertable into an eyelet provided on the tool housing for releasably connecting the attachment means with the power tool, the bolt having axial conduit means and a radial conduit means for communicating the axial conduit means with an outer cylindrical surface of the bolt. Thereby in a predetermined position of the bolt in the eyelet, a drilling fluid can be delivered through the bolt to the fluid conduit means of the power tool.
According to the present invention, there is provided fluid conduit means for delivering a drilling or cooling fluid from the displacement carriage to the power tool and further to the working tool via conduit means provided in the attachment member and the connecting bolt. The present invention eliminates separate connection and disconnection of the fluid conduit means of the power tool with the cooling fluid delivering conduit means during mounting of the power tool on the carriage and dismounting it therefrom.
Advantageously, there is provided closing means that prevents the bolt from being lost upon a complete withdrawal of the bolt. This is particularly important for insuring the service readiness of the power tool.
Alternatively, the bolt can be formed as a pin having a section projecting beyond the attachment member and fixedly connected with the attachment member, which is formed as a fork head half. The pin-shaped bolt has a through bore for receiving a security splint. This permits a single operator to connect a heavy power tool to the carriage in a first step and secure the power tool thereto in a second step.
Advantageously, the bolt is associated with a locking pin that is formlockingly received in an eyelet formed in the power tool housing and extending parallel to the eyelet the bolt is received in. This permits to properly secure the power tool on the support.
Advantageously, the bolt and the locking pin form legs of a U-shaped insertion member, which permits to insert both the bolt and the locking pin in the attachment member and the respective eyelets of the housing in a single operational step.
Alternatively, the bolt can be formlockingly pivotally received in the housing eyelet which permits, by changing the angular position of the bolt, to block flow of the cooling fluid to the power tool. This eliminates a need in additional fluid flow blocking means. In this case, the bolt forms a middle part of a U-shaped lever with a first leg of the U-shaped lever forms a locking lever for pivoting the bolt and a second leg forms a stop for preventing a complete withdrawal of the bolt.